1 Calories In Versus Calories Out
University of Hawai‘i at Mānoa Food Science and Human Nutrition Program and Human Nutrition Program
The ability to estimate energy expenditure and quantify calories consumed, has led to the simple conclusion that tracking or counting “calories in” compared to “calories out” will result in an easy way to manage body weight. This logic does not take into account the complexity and individuality of the human body. Human bodies are not static, meaning there are fluctuations from day to day in energy needs related to set point, sleep patterns, stress levels, activity levels, and eating patterns. Something as simple as the timing and macronutrient composition of meals, will impact the thermic effect of food, resulting in a change in energy expenditure.
Dieting Basics/ Dieting 101
The diet and weight loss industry is big business. In 2017, The U.S. Weight Loss and Diet Control Market reported a record $72 billion dollar value to the weight loss market.[1] This dollar amount is expected to continue to rise. At the same time, there is evidence that diets do not lead to long term weight loss for the majority of people. In observational studies, dieting was the best predictor of future weight gain and onset of obesity.[2][3][4] Meta-analysis and reviews of randomized clinical trials reported that on average, obesity treatments cause weight gain.[5][6] This additional weight gain leads to an increase in the set point, making it more difficult for an individual to lose weight in the future. Others reported a 3-5 % weight loss was possible 4 years later if participants continued all aspects of treatment.[7] For a 200 pound person, this represents a 6-10 pound weight loss. The health benefits of this modest weight loss are unclear and it is far less what is expected or desired when following a diet. In conclusion, the diet industry makes money from a product that is proven not to work.
Dieting and Health
The scientific evidence shows that diets lead to modest weight loss for some and future weight gain for the majority of people. This often leads to a behavior called weight cycling or yo-yo dieting. The person continues to seek weight loss and a new diet, hoping to get a new result. This repetition of starting and stopping diets leads to losing and gaining a similar amount of weight over and over again. The weight goes up and down like a yo-yo. In addition, when someone cuts out food groups and restricts certain foods from their diet, the interest in the food increases. This in combination with intense hunger resulting from energy restriction, leads to a feeling of being out of control around foods and binge eating. To compensate for the feeling out of control, the person then restricts the food again and is then in a restriction/ binge or overeating cycle.
The majority (up to 95%) of people regain the weight within three years and often gain back more.[8][9] Weight cycling puts stress on the body causing physical complications